Question. The website says that the N2plus has an all metal hot end and can go to 300 C. I thought that hot ends with a PTFE lining are not considered "all metal". Is it because the PTFE lining is higher up than other hot ends?

It's not a liner if it's not in the hotend. Therefore, a simple filament guide path from the extruder feeder to the hotend does not make it a PTFE lined hotend. Yes, the entire N series always has been all metal, even the very first kickstarter units that shipped with a V1 Hotend, even it's all metal.